/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: DTMTreeWalker.java,v 1.2.4.1 2005/09/15 08:15:05 suresh_emailid Exp $
 */
package com.sun.org.apache.xml.internal.dtm.ref;

import com.sun.org.apache.xml.internal.dtm.DTM;
import com.sun.org.apache.xml.internal.utils.NodeConsumer;
import com.sun.org.apache.xml.internal.utils.XMLString;

import org.xml.sax.ContentHandler;
import org.xml.sax.ext.LexicalHandler;

/**
 * This class does a pre-order walk of the DTM tree, calling a ContentHandler
 * interface as it goes. As such, it's more like the Visitor design pattern
 * than like the DOM's TreeWalker.
 *
 * I think normally this class should not be needed, because
 * of DTM#dispatchToEvents.
 * @xsl.usage advanced
 */
public class DTMTreeWalker {

    /** Local reference to a ContentHandler          */
    private ContentHandler m_contentHandler = null;

    /** DomHelper for this TreeWalker          */
    protected DTM m_dtm;

    /**
     * Set the DTM to be traversed.
     *
     * @param dtm The Document Table Model to be used.
     */
    public void setDTM(DTM dtm) {
        m_dtm = dtm;
    }

    /**
     * Get the ContentHandler used for the tree walk.
     *
     * @return the ContentHandler used for the tree walk
     */
    public ContentHandler getcontentHandler() {
        return m_contentHandler;
    }

    /**
     * Set the ContentHandler used for the tree walk.
     *
     * @param ch the ContentHandler to be the result of the tree walk.
     */
    public void setcontentHandler(ContentHandler ch) {
        m_contentHandler = ch;
    }

    /**
     * Constructor.
     */
    public DTMTreeWalker() {
    }

    /**
     * Constructor.
     * @param   contentHandler The implemention of the
     * contentHandler operation (toXMLString, digest, ...)
     */
    public DTMTreeWalker(ContentHandler contentHandler, DTM dtm) {
        this.m_contentHandler = contentHandler;
        m_dtm = dtm;
    }

    /** Perform a non-recursive pre-order/post-order traversal,
     * operating as a Visitor. startNode (preorder) and endNode
     * (postorder) are invoked for each node as we traverse over them,
     * with the result that the node is written out to m_contentHandler.
     *
     * @param pos Node in the tree at which to start (and end) traversal --
     * in other words, the root of the subtree to traverse over.
     *
     * @throws TransformerException */
    public void traverse(int pos) throws org.xml.sax.SAXException {
        // %REVIEW% Why isn't this just traverse(pos,pos)?

        int top = pos; // Remember the root of this subtree

        while (DTM.NULL != pos) {
            startNode(pos);
            int nextNode = m_dtm.getFirstChild(pos);
            while (DTM.NULL == nextNode) {
                endNode(pos);

                if (top == pos)
                    break;

                nextNode = m_dtm.getNextSibling(pos);

                if (DTM.NULL == nextNode) {
                    pos = m_dtm.getParent(pos);

                    if ((DTM.NULL == pos) || (top == pos)) {
                        // %REVIEW% This condition isn't tested in traverse(pos,top)
                        // -- bug?
                        if (DTM.NULL != pos)
                            endNode(pos);

                        nextNode = DTM.NULL;

                        break;
                    }
                }
            }

            pos = nextNode;
        }
    }

    /** Perform a non-recursive pre-order/post-order traversal,
     * operating as a Visitor. startNode (preorder) and endNode
     * (postorder) are invoked for each node as we traverse over them,
     * with the result that the node is written out to m_contentHandler.
     *
     * @param pos Node in the tree where to start traversal
     * @param top Node in the tree where to end traversal.
     * If top==DTM.NULL, run through end of document.
     *
     * @throws TransformerException
     */
    public void traverse(int pos, int top) throws org.xml.sax.SAXException {
        // %OPT% Can we simplify the loop conditionals by adding:
        //          if(top==DTM.NULL) top=0
        // -- or by simply ignoring this case and relying on the fact that
        // pos will never equal DTM.NULL until we're ready to exit?

        while (DTM.NULL != pos) {
            startNode(pos);
            int nextNode = m_dtm.getFirstChild(pos);
            while (DTM.NULL == nextNode) {
                endNode(pos);

                if ((DTM.NULL != top) && top == pos)
                    break;

                nextNode = m_dtm.getNextSibling(pos);

                if (DTM.NULL == nextNode) {
                    pos = m_dtm.getParent(pos);

                    if ((DTM.NULL == pos) || ((DTM.NULL != top) && (top == pos))) {
                        nextNode = DTM.NULL;

                        break;
                    }
                }
            }

            pos = nextNode;
        }
    }

    /** Flag indicating whether following text to be processed is raw text          */
    boolean nextIsRaw = false;

    /**
     * Optimized dispatch of characters.
     */
    private final void dispatachChars(int node) throws org.xml.sax.SAXException {
        m_dtm.dispatchCharactersEvents(node, m_contentHandler, false);
    }

    /**
     * Start processing given node
     *
     *
     * @param node Node to process
     *
     * @throws org.xml.sax.SAXException
     */
    protected void startNode(int node) throws org.xml.sax.SAXException {

        if (m_contentHandler instanceof NodeConsumer) {
            // %TBD%
            //      ((NodeConsumer) m_contentHandler).setOriginatingNode(node);
        }

        switch (m_dtm.getNodeType(node)) {
            case DTM.COMMENT_NODE: {
                XMLString data = m_dtm.getStringValue(node);

                if (m_contentHandler instanceof LexicalHandler) {
                    LexicalHandler lh = ((LexicalHandler) this.m_contentHandler);
                    data.dispatchAsComment(lh);
                }
            }
                break;
            case DTM.DOCUMENT_FRAGMENT_NODE:

                // ??;
                break;
            case DTM.DOCUMENT_NODE:
                this.m_contentHandler.startDocument();
                break;
            case DTM.ELEMENT_NODE:
                DTM dtm = m_dtm;

                for (int nsn = dtm.getFirstNamespaceNode(node, true); DTM.NULL != nsn; nsn = dtm.getNextNamespaceNode(node, nsn, true)) {
                    // String prefix = dtm.getPrefix(nsn);
                    String prefix = dtm.getNodeNameX(nsn);

                    this.m_contentHandler.startPrefixMapping(prefix, dtm.getNodeValue(nsn));

                }

                // System.out.println("m_dh.getNamespaceOfNode(node): "+m_dh.getNamespaceOfNode(node));
                // System.out.println("m_dh.getLocalNameOfNode(node): "+m_dh.getLocalNameOfNode(node));
                String ns = dtm.getNamespaceURI(node);
                if (null == ns)
                    ns = "";

                // %OPT% !!
                org.xml.sax.helpers.AttributesImpl attrs = new org.xml.sax.helpers.AttributesImpl();

                for (int i = dtm.getFirstAttribute(node); i != DTM.NULL; i = dtm.getNextAttribute(i)) {
                    attrs.addAttribute(dtm.getNamespaceURI(i), dtm.getLocalName(i), dtm.getNodeName(i), "CDATA", dtm.getNodeValue(i));
                }

                this.m_contentHandler.startElement(ns, m_dtm.getLocalName(node), m_dtm.getNodeName(node), attrs);
                break;
            case DTM.PROCESSING_INSTRUCTION_NODE: {
                String name = m_dtm.getNodeName(node);

                // String data = pi.getData();
                if (name.equals("xslt-next-is-raw")) {
                    nextIsRaw = true;
                } else {
                    this.m_contentHandler.processingInstruction(name, m_dtm.getNodeValue(node));
                }
            }
                break;
            case DTM.CDATA_SECTION_NODE: {
                boolean isLexH = (m_contentHandler instanceof LexicalHandler);
                LexicalHandler lh = isLexH ? ((LexicalHandler) this.m_contentHandler) : null;

                if (isLexH) {
                    lh.startCDATA();
                }

                dispatachChars(node);

                {
                    if (isLexH) {
                        lh.endCDATA();
                    }
                }
            }
                break;
            case DTM.TEXT_NODE: {
                if (nextIsRaw) {
                    nextIsRaw = false;

                    m_contentHandler.processingInstruction(javax.xml.transform.Result.PI_DISABLE_OUTPUT_ESCAPING, "");
                    dispatachChars(node);
                    m_contentHandler.processingInstruction(javax.xml.transform.Result.PI_ENABLE_OUTPUT_ESCAPING, "");
                } else {
                    dispatachChars(node);
                }
            }
                break;
            case DTM.ENTITY_REFERENCE_NODE: {
                if (m_contentHandler instanceof LexicalHandler) {
                    ((LexicalHandler) this.m_contentHandler).startEntity(m_dtm.getNodeName(node));
                } else {

                    // warning("Can not output entity to a pure SAX ContentHandler");
                }
            }
                break;
            default:
        }
    }

    /**
     * End processing of given node
     *
     *
     * @param node Node we just finished processing
     *
     * @throws org.xml.sax.SAXException
     */
    protected void endNode(int node) throws org.xml.sax.SAXException {

        switch (m_dtm.getNodeType(node)) {
            case DTM.DOCUMENT_NODE:
                this.m_contentHandler.endDocument();
                break;
            case DTM.ELEMENT_NODE:
                String ns = m_dtm.getNamespaceURI(node);
                if (null == ns)
                    ns = "";
                this.m_contentHandler.endElement(ns, m_dtm.getLocalName(node), m_dtm.getNodeName(node));

                for (int nsn = m_dtm.getFirstNamespaceNode(node, true); DTM.NULL != nsn; nsn = m_dtm.getNextNamespaceNode(node, nsn, true)) {
                    // String prefix = m_dtm.getPrefix(nsn);
                    String prefix = m_dtm.getNodeNameX(nsn);

                    this.m_contentHandler.endPrefixMapping(prefix);
                }
                break;
            case DTM.CDATA_SECTION_NODE:
                break;
            case DTM.ENTITY_REFERENCE_NODE: {
                if (m_contentHandler instanceof LexicalHandler) {
                    LexicalHandler lh = ((LexicalHandler) this.m_contentHandler);

                    lh.endEntity(m_dtm.getNodeName(node));
                }
            }
                break;
            default:
        }
    }
} //TreeWalker
